SACRAMENTO, Calif., Aug 12 (Reuters) - California Democrats scrambled on Tuesday to win Republican support for a plan to improve water supplies that has been mired in regional and party politics for a year, even as the state suffers from a three-year drought that shows no sign of ending.

A day after voting for a two-day extension to put a proposal on November's ballot to pay for reservoirs and other projects by selling bonds, Democratic lawmakers enlisted the support and negotiating clout of Democratic Governor Jerry Brown, a fiscal moderate who said previous plans were too expensive.

"We're very close," said Brown after meeting with Republican leaders who want more reservoirs and Democratic holdouts who say damming rivers and flooding canyons to build them is damaging to the environment. "There's been a lot of compromise."

California is in the throes of a devastating drought that is expected to cost its economy $2.2 billion in lost crops, jobs and other damage.

Lawmakers from both parties say this may be the only year that tax-averse voters, aware of the drought's impact, would be willing to pay for new water projects, yet they continue to fight over which ones to include.

An $11 billion plan negotiated under Republican former governor Arnold Schwarzenegger in 2009 is set to go before voters in November, but Democrats, who now control both houses of the legislature and all statewide elected offices, say it is too expensive and full of pork.

Brown has said he would campaign against it, and polls show little public support. Democrats who represent the area around the fragile San Joaquin-Sacramento River Delta say some of the projects included in it would damage vital habitat for endangered animals and risk water supplies.

The legislature has been working since last summer to develop a cheaper alternative, but a two-thirds majority vote is required before such a measure can be placed on the ballot - and Democrats are short two votes in the state Senate thanks to a series of scandals that sidelined three of their members.

Peter De Marco, a spokesman for senate Republican leader Bob Huff, said the main sticking point is the amount of money to be spent on water storage, including reservoirs.

"It's a critical piece for California that has been neglected for a long time," De Marco said. Republican leaders planned to continue negotiating with the Brown administration Tuesday afternoon, he said.

The latest version of the bond has $2.5 billion for such projects, but Republicans have held out for $3 billion, the amount in the Schwarzenegger proposal. Some Republicans also want the plan to include an environmental project that would later allow the state to build tunnels or canals to carry water to the Central Valley, a major farming area that relies on irrigation. (Editing by Eric Walsh)

We welcome comments that advance the story through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can flag it to our editors by using the report abuse links. Views expressed in the comments do not represent those of the Thomson Reuters Foundation. For more information see our Acceptable Use Policy.